Fig. 5. Timeline of behavioural and morphological development. Timeline showing major changes in contraction patterns identified by muscle imaging, and onset of larval-like reflexes. Morphological development 16-18.5 hours AEL [roughly corresponding to stages 17b-d of Pereanu et al. (Pereanu et al., 2007)]. At 16.0 hours AEL, spiracles are detected as dorsal papillae on the terminal segment. At 16.5 hours, uric acid is detected in the Malpighian tubules, becoming strong by 17.0 hours. At 17.5 hours the median tooth tip becomes faintly visible anteriorly. By 18.0 hours the tooth is clear but tracheae have not filled. At 18.5 hours, tracheae fill.